The　rotation　degree　of　freedom　in　discontinuous　deformation　analysis　(DDA)　may　cause　false　volume　expansion　when　a　block　undergoes　a　large　rotation.　We　propose　a　block　displacement　function　to　prevent　this　defect.　Specifically,　the　degrees　of　freedom　in　a　block　are　redefined　by　incremental　displacements　at　its　vertices,　and　displacement　is　formulated　based　on　the　mean　value　coordinates.　In　addition,　the　finite　element　method　with　updated　Lagrangian　formulation　is　employed　to　derive　the　equilibrium　equations,　while　the　contact　analysis　and　implicit　time　integration　for　dynamics　is　maintained　from　the　original　DDA.　After　each　time　step,　the　block　configuration　is　updated　by　adding　the　new　degrees　of　freedom　to　the　previous　coordinates　of　the　block　vertices.　Results　from　numerical　examples　confirm　the　effectiveness　of　the　proposed　approach　to　prevent　false　volume　expansion,　ensure　correctness　of　contact　analysis,　and　provide　realistic　stress　results　when　simulating　large　rotations.